Abstract
A respirometric approach has been developed to determine heterotrophic biofilm kinetics using fluidized bioparticles - particles with attached biomass. Lava rock particles of 600 m were used as a biomass carrier medium. The modified respirometer successfully estimates in situ biofilm kinetics of the bioparticles collected from a pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor. The observed maximum specific growth rates (μmax) of 3.69 ± 0.44d-1 and biomass yields (YH) of 0.36 ± 0.03g COD/g COD in the fluidized bed respirometers were significantly different from the μmax of 5.57-5.72d1 and YH of 0.54-0.59g COD/g COD observed in the conventional respirometric tests for bioparticles and detached biomass. The higher Monod half-saturation coefficient (KS) of 186-219mg COD/L observed in the fluidized bed respirometers relative to the 49-58mg COD/L in the conventional respirometers reveals the presence of mass transfer resistance in the LSCFB despite fluidization. Significantly reduced yields in the fluidized bed respirometers and the estimated maintenance coefficient of 1.16d -1 for the particulate biofilm in the LSCFB clearly emphasize that a substantial amount of substrate was utilized for cell maintenance at the low food to microorganism (S/X) ratio of 0.5g COD/g VSS.
Original language | English |
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Pages (from-to) | 455-465 |
Number of pages | 11 |
Journal | Environmental Technology (United Kingdom) |
Volume | 33 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1 Feb 2012 |
Externally published | Yes |
Keywords
- biokinetics
- diffusion
- fixed-film respirometry
- food to microorganism ratio
- maintenance coefficient
ASJC Scopus subject areas
- Environmental Chemistry
- Water Science and Technology
- Waste Management and Disposal